Standardize usage of virtual/override/final in ui/

ui/gl/gl_surface_osmesa.h

Index: ui/gl/gl_surface_osmesa.h
diff --git a/ui/gl/gl_surface_osmesa.h b/ui/gl/gl_surface_osmesa.h
index 20fb17f7f2ef9e6f50e995a7832b7b1d97a9d26a..80d10872c7a5c32a36a13b1e9dcbfaf5aae46d53 100644
--- a/ui/gl/gl_surface_osmesa.h
+++ b/ui/gl/gl_surface_osmesa.h
@@ -21,17 +21,17 @@ class GL_EXPORT GLSurfaceOSMesa : public GLSurface {
   GLSurfaceOSMesa(OSMesaSurfaceFormat format, const gfx::Size& size);
 
   // Implement GLSurface.
-  virtual bool Initialize() override;
-  virtual void Destroy() override;
-  virtual bool Resize(const gfx::Size& new_size) override;
-  virtual bool IsOffscreen() override;
-  virtual bool SwapBuffers() override;
-  virtual gfx::Size GetSize() override;
-  virtual void* GetHandle() override;
-  virtual unsigned GetFormat() override;
+  bool Initialize() override;
+  void Destroy() override;
+  bool Resize(const gfx::Size& new_size) override;
+  bool IsOffscreen() override;
+  bool SwapBuffers() override;
+  gfx::Size GetSize() override;
+  void* GetHandle() override;
+  unsigned GetFormat() override;
 
  protected:
-  virtual ~GLSurfaceOSMesa();
+  ~GLSurfaceOSMesa() override;
 
  private:
   unsigned format_;
@@ -48,11 +48,11 @@ class GLSurfaceOSMesaHeadless : public GLSurfaceOSMesa {
  public:
   explicit GLSurfaceOSMesaHeadless();
 
-  virtual bool IsOffscreen() override;
-  virtual bool SwapBuffers() override;
+  bool IsOffscreen() override;
+  bool SwapBuffers() override;
 
  protected:
-  virtual ~GLSurfaceOSMesaHeadless();
+  ~GLSurfaceOSMesaHeadless() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceOSMesaHeadless);